The feed intake of sheep supplemented with varying quantities of wheat while grazing pastures differing in herbage availability

Abstract

Diets containing various quantities of lucerne chaff and wheat grain were given to three sheep in a digestibility trial. Daily faecal output was related to daily intakes of chaff and wheat by regression analysis. The partial regression coefficient for wheat was used to estimate the faecal output attributable to wheat in a grazing trial in which flocks of five sheep grazed at five stocking rates and received either 0, 100, 200, 300, or 400 g wheat per day. The sheep were allocated to treatments and periods at each stocking rate in a Latin square design. Herbage intake was estimated in each period.

Herbage intake decreased when supplementary feeding or stocking rate was increased. Supplementary feeding increased the nutrient intake of grazing sheep by an average of 54% of the nutrient content of the wheat given. This percentage was greater when pasture availability was low. At high stocking rates the decline in herbage intake was less than at low stocking rates in absolute terms although greater when expressed as a percentage of the herbage intake of the unsupplemented sheep